private void open()

in spark-doris-connector/spark-doris-connector-base/src/main/java/org/apache/doris/spark/client/DorisBackendThriftClient.java [70:107]
38 lines of code
8 McCabe index (conditional complexity)

    private void open() throws ConnectedFailedException {
        logger.debug("Open client to Doris BE '{}'.", backend);
        Exception ex = null;
        for (int attempt = 0; !isConnected && attempt < retries; ++attempt) {
            logger.debug("Attempt {} to connect {}.", attempt, backend);
            try {
                TBinaryProtocol.Factory factory = new TBinaryProtocol.Factory();
                TConfiguration tConf = new TConfiguration();
                Integer maxMessageSize = config.getValue(DorisOptions.DORIS_THRIFT_MAX_MESSAGE_SIZE);
                tConf.setMaxMessageSize(maxMessageSize);
                Integer connectTimeout = config.getValue(DorisOptions.DORIS_REQUEST_CONNECT_TIMEOUT_MS);
                Integer socketTimeout = config.getValue(DorisOptions.DORIS_REQUEST_READ_TIMEOUT_MS);
                logger.trace("connect timeout set to '{}'. socket timeout set to '{}'. retries set to '{}'.",
                        connectTimeout, socketTimeout, this.retries);
                transport = new TSocket(tConf, backend.getHost(), backend.getRpcPort(), socketTimeout, connectTimeout);
                TProtocol protocol = factory.getProtocol(transport);
                client = new TDorisExternalService.Client(protocol);
                logger.trace("Connect status before open transport to {} is '{}'.", backend, isConnected);
                if (!transport.isOpen()) {
                    transport.open();
                    isConnected = true;
                }
            } catch (TTransportException e) {
                logger.warn(ErrorMessages.CONNECT_FAILED_MESSAGE, backend, e);
                ex = e;
            } catch (OptionRequiredException e) {
                ex = e;
            }
            if (isConnected) {
                logger.info("Success connect to {}.", backend);
                break;
            }
        }
        if (!isConnected) {
            logger.error(ErrorMessages.CONNECT_FAILED_MESSAGE, backend);
            throw new ConnectedFailedException(backend.toString(), ex);
        }
    }